So stressed and worried

This might be long so apologies in advance!I have a little bit who is almost 4. He is a moving, happy, bright little boy. He has loads of friend at nursery, gets invited to.parties, kids are coming to his party. He is exactly where he should be on the EYFS.

Except for his social and emotional development and concentration.

Nursery have been having lots of problems with him leaving activities before they are finished, not listening /following instructions and becoming very angry and distressed if they try to insist he does something. It seems to have got worse over time to the point that he sometimes throws toys/hits staff obviously this is totally unacceptable and I have every sympathy with them. He does not do these things at home/his swimming lesson/when out with me/at parties etc. He does have a short concentration span though!

We are about to start the assessment process with the child development service to have him assessed for additional needs.

Nursery have now said they are not the right setting for him and have told me that after Xmas he can only do up to 2 days there. So, I am looking at the preschool attached to the school he will attend as it is smaller/more flexible/less staff. I need to ring on Mon.

I'm just so stressed and worried - he's genuinely a lovely little boy but clearly has some difficulties somewhere and I feel so worried for him.